Williams’ body was found by his personal assistant, who made the 911 call. Williams was pronounced dead at 12:02 p.m, and police are ruling the preliminary cause of death as suicide due to asphyxia.

Boyd stressed toxicology tests to determine if Williams had drugs or alcohol in his system could take two to six weeks, and investigation is ongoing. Williams, who was last seen alive by his wife around 10:30 p.m. Sunday, had “been seeking treatment for depression.” (RELATED: Remembering Robin Williams: His Greatest Roles)